LSSTApplications  19.0.0-10-g4a5fae6+3,19.0.0-10-g920eed2,19.0.0-11-g48a0200+2,19.0.0-18-gfc4e62b+16,19.0.0-2-g3b2f90d+2,19.0.0-2-gd671419+6,19.0.0-20-g5a5a17ab+14,19.0.0-21-g2644856+17,19.0.0-24-g0913cb1,19.0.0-24-g878c510+4,19.0.0-25-g6c8df7140+1,19.0.0-25-gb330496+4,19.0.0-3-g2b32d65+6,19.0.0-3-g8227491+15,19.0.0-3-g9c54d0d+15,19.0.0-3-gca68e65+11,19.0.0-3-gcfc5f51+6,19.0.0-3-ge110943+14,19.0.0-3-ge74d124,19.0.0-30-g9c3fd16+5,19.0.0-4-g06f5963+6,19.0.0-4-g10df615,19.0.0-4-g3d16501+17,19.0.0-4-g4a9c019+6,19.0.0-4-g5a8b323,19.0.0-4-g66397f0+1,19.0.0-4-g8557e14,19.0.0-4-g8964aba+16,19.0.0-4-ge404a01+15,19.0.0-5-g40f3a5a,19.0.0-5-g4db63b3,19.0.0-5-gb9eeb60,19.0.0-5-gfb03ce7+16,19.0.0-6-gbaebbfb+15,19.0.0-61-gec4c6e08+5,19.0.0-7-g039c0b5+15,19.0.0-7-gbea9075+4,19.0.0-7-gc567de5+16,19.0.0-72-g37abf38+2,19.0.0-9-g463f923+15,v20.0.0.rc1
LSSTDataManagementBasePackage
hashCombine.h
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1 /*
2  * LSST Data Management System
3  * See COPYRIGHT file at the top of the source tree.
4  *
5  * This product includes software developed by the
6  * LSST Project (http://www.lsst.org/).
7  *
8  * This program is free software: you can redistribute it and/or modify
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22 #ifndef LSST_UTILS_HASH_COMBINE_H
23 #define LSST_UTILS_HASH_COMBINE_H
24 
25 #include <functional>
26 
27 namespace lsst {
28 namespace utils {
29 
35 inline std::size_t hashCombine(std::size_t seed) noexcept { return seed; }
36 
59 // This implementation is provided by Matteo Italia, https://stackoverflow.com/a/38140932/834250
60 // Algorithm described at https://stackoverflow.com/a/27952689
61 // WARNING: should not be inline or constexpr; it can cause instantiation-order problems with std::hash<T>
62 template <typename T, typename... Rest>
63 std::size_t hashCombine(std::size_t seed, const T& value, Rest... rest) noexcept {
64  std::hash<T> hasher;
65  seed ^= hasher(value) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
66  return hashCombine(seed, rest...);
67 }
68 
90 // Note: not an overload of hashCombine to avoid ambiguity with hashCombine(size_t, T1, T2)
91 // WARNING: should not be inline or constexpr; it can cause instantiation-order problems with std::hash<T>
92 template <typename InputIterator>
93 std::size_t hashIterable(std::size_t seed, InputIterator begin, InputIterator end) noexcept {
94  std::size_t result = 0;
95  for (; begin != end; ++begin) {
96  result = hashCombine(result, *begin);
97  }
98  return result;
99 }
100 
101 }} // namespace lsst::utils
102 
103 #endif
end
int end
Definition: BoundedField.cc:105
result
py::object result
Definition: _schema.cc:429
lsst::utils::hashIterable
std::size_t hashIterable(std::size_t seed, InputIterator begin, InputIterator end) noexcept
Combine hashes in an iterable.
Definition: hashCombine.h:93
lsst
A base class for image defects.
Definition: imageAlgorithm.dox:1
lsst::utils::hashCombine
std::size_t hashCombine(std::size_t seed) noexcept
Combine hashes.
Definition: hashCombine.h:35
std::size_t
std::hash